Killing the appliction

I'd like to kill my app whenever the user use the Exit item in my app's menu.
How it can be done?
Currently, I'm using System.exit(0). But, the result of using it, is rerun the application.
Thanks,
Eyal.

Well, according to the Android application life cycle, onDestroy() is the last thing to be called before the app finally dies, and I read that it responds to, for instance, a call from YourActivity.finish().